Broken links to reference materials on generating documentation

[cmlight]

There are links on the page https://cobra.dev/ which result in a 404 upon navigation. These include:

  | <li><a href="doc/md_docs.md">Markdown</a></li>
  | <li><a href="doc/rest_docs.md">ReStructured Text</a></li>
  | <li><a href="doc/man_docs.md">Man Page</a></li>

and the bash_completions.md link:

<a href="bash_completions.md">Bash Completions</a>

I wasn't able to locate in the source repo any files matching these names which were the potential intended targets; otherwise, I would offer a pull request to fix.

[umarcor]

See #1.